Ah, yes, this will be as useful as that full-screen mode in the classic editor that everybody didn't like.

Forcing creators to use full-screen mode is an example bad UI design decision making. End-users must be in full control of their dashboard settings.

Overriding the end user's preferences and settings is rarely ever a good idea and is often forever remembered in all the wrong ways.

Remember that time WordPress wanted to force people to use Gutenberg..?

Remember that time WordPress wanted to force people to use full-screen mode..?

Remember that CMS everyone used to use. What was it called..? WordThingy or something..?

I'm a fan of Gutenberg. I predicted WordPress would move toward the page builder + minimalist theme stack many years ago. Long before Gutenberg arrived. But, keep making bad decisions like this that remove choice from end-users or that override end-user settings and WordPress will go the way of that other CMS.. what was that CMS called again.. WordThingy or something?

Let end-users make their own decisions. Offer full-screen mode as an option. Give it big button to switch it on and off. Don't tell people they must disable it after they have become accustomed to never having need to enable it, ever.